Currently, in scenarios where security inspection devices are utilized, such as airport, stadium and gymnasium, there are usually several security inspection devices arranged on the spot, while a control cabinet is remotely located. According to operation requirements, the security inspection devices, also be referred as local devices, need to be powered on before start of daily work and powered off before end of daily work. Since power switches of these devices are at the local side, the operator of the control cabinet has to move to the site for operations such as power-on/off of the devices, which leads to workload increase of the operator. Furthermore, there exist a variety of additional requirements. For example, it is desirable to perform control operations such as power-on/off of the local devices at the local side, or control operations such as power/off of the local devices at the remote side. It is also desirable to collectively control, power-on/off and batch-select the local devices from the remote side, or remotely perform operations such as emergency stop and status diagnosis between the remote side and the local devices.
Conventionally, in order to satisfy the above discussed requirements, power-on/off control of the local devices may be implemented by converging power-on/off signals from the local devices to the remote control site via several signal lines, and combining power-on/off signals from both the local and remote sides with reference to the power-on/off lights on a panel of the remote control site. If each local device has 4 signal lines for power-on/off, 4*N signal lines are connected to the remote side for N(N≧2) local devices. Furthermore, there are signals, such as failure, status, etc., to be fed back from the local devices to the remote control site. As a result, the number of signal lines becomes very large. In traditional solutions, each signal occupies one signal line, resulting in a large number of signal lines, complicated layout of lines, difficulty in diagnosis when some problem arises, and vulnerability of signals to interference during a long-distance transmission which probably leads to erroneous control status.
There is a need for a method capable of utilizing less signal lines and simpler layout of lines to achieve correct and reliable centralized management of local devices from a remote control site.